1. I use to use dump in 4.x, but since my upgrade to 5.x, I can't
find it?
The /etc/dump and /etc/restore commands were renamed /usr/sbin/ufsdump
and /usr/sbin/ufsrestore.
Files created with the SunOS release 4.x dump command can be restored on
a SunOS release 5.x system with /usr/sbin/ulfsrestore.
The ufsdump command accepts the same command syntax as the SunOS release
4.x dump command. See man page for more information on options and
syntax examples.

2. How can I dump data from my SUN/Solaris system, then read on a non-SUN system?
To start with, ensure that tape drives (if appl) are compatible with
each other...including the media itself. For example, an 8505xl on
a Solaris system cannot be read by an EXB-8200 on SGI UNLESS you
write the data to the tape using the low density mode (/dev/rmt/01).
Archives created with the SunOS 5.x cpio command may not be compatible
with older SunOS releases. The cpio command allows you to create
archives that can be read with several other formats. You specify these
formats using the -H option and one of these arguments:
- crc or CRC -- ASCII header with checksum
- ustar or USTAR -- IEEE/P1003 Data Interchange
- tar or TAR -- tar header and format
- odc -- ASCII header with small device numbers
- bar -- bar header and format
The syntax for using the header options is: cpio -o -H header-option <
file-list > output-archive
How to Create an Archive Compatible with Older SunOS Releases (or NON-SUN)
Type cpio -oH odc < file-list > /dev/rmt/n and press Return.
The -H options have the same meaning for input as they do for output. If
the archive was created using the -H option, you must use the same
option when the archive is read back in or the cpio command will fail,
as shown in this example:

When you create an archive using different options, always write the
command syntax on the media label along with the names of the files or
file system on the archive.
If you do not know which cpio options were used when an archive was
created, all you can do is experiment with different combinations of the
options to see which ones allow the archive to be read.

3. What blocking factor (density) is best for my type of tape drive?
Generally speaking, larger blocking factors = better storage capacity.
There is an interrecord gap written on the tape between blocks. If you
write more blocks (because they are smaller), you write more gaps, and
thus you have less info on the tape.
Use these specification as guidelines. Your mileage can vary, but this
generally works best (126 is the default)
Drive type: 8mm DLT 4mm
Use Blkg Factor: 126 126 96
4mm(DAT) tape drives use 96 (recommended for optimum 4mm performance)
DLT tape drives, use default of 126

5. Why does my tape drive error? I just installed it.
Very often customers have a tendency to take their new tape drive and
plug it into their old machines, with varying results. Most commonly
the error resulting from a new tape device on an old OS (which does not
support this tape device is: ..." data transfer overrun"....

6. What does the "b" do when I specify my tape device as: /dev/rmt/0bn?
With the BSD device, when the read operation hits the file mark, it
leaves the read head positioned after the file mark, so that the next
read gets the data from the next tape file.
The SysV device leaves the head before the file mark, so that any subsequent
read operations return 0 or -1. You have to explicitly reposition the head
to the other side the file mark using 'mt fsf' or the equivalent ioctl()
before you can read more data.
Another explanation:
What this means is that during a read operation, if the last block is
encountered and another read is issued, the driver will return an error
if the Berkeley flag is not used. Unless it is a EOM mark.
Typically, software applications that are looking for information from a
tape device will exhibit this behavior (read BudTool).
So, the Berkeley device flag says that it's ok to do this.

7. Is it was possible to do an image backup of an entire disk using the dd command?
With the standard layout, Solaris continues in the tradition of the
Berkeley based operating systems where partition 'c' (slice 2) actually
represents all of the blocks on the disk drive. You should not newfs
this. The newfs would create a file system that spans the entire disk
drive. If you did this after having newfs other slice, you would destroy
information on these other slices. The "dd" command can backup the
entire disk using slice 2. It looks like this
# dd bs=80b if=/dev/rdsk/c0t3d0s2 of=/dev/rmt/0m
Where:
bs stands for blocksize
if stands for input file
of stands for output file
The choice of block size should be based on the disk geometry. Usually,
I use an integer multiple of the track size in sectors. You do have to
pay close attention to the maximum allowable block size on the tape. Be
aware that the "b" suffix, indicates a 512 byte block (same as the
sector size).
You should be aware that the backup of the "image" of the disk should
only occur while the "file systems" on that disk are offline or
"unmounted". If they are mounted, activity on the drive would corrupt
your backup. For the disk drive holding the root file system, the only
way to get it off-line is to do the backup while booted in single user
mode from the cdrom (or other installation media). This is a very
serious defect of this technique of image backups.
The "ufsdump" utility cannot be used to backup the entire disk. It is
designed to backup a single "file system" not a disk drive with multiple
file systems. The "dd" utility is just a copy utility that works on
images.
Of course this should bring up the topic of restorations and verification.
To verify an image tape use "dd" and the /dev/null device.
# dd bs=80b if=/dev/rmt/0m of=/dev/null
The "dd" command will report the number of blocks read from tape and
written to the null device. This should match the values reported when
creating the image backup. This verifies that the tape is readable, but
does not do an integrity check.
To restore an image backup you would issue:
# dd bs=80b of=/dev/rdsk/c0t3d0s2 if=/dev/rmt/0m
This should be done with all drives on the disk off-line (unmounted)
just as in the backup.

8. How do I use find and cpio together?
See AnswerBook for very clear examples and descriptions of cpio usage
and its usability.
USING CPIO TO WRITE FILES TO A TAPE.
The cpio command, used to create an archive, takes a list of files or
path names from standard input and writes to standard output. The output
is almost always redirected to a file or to a device.
Type:
ls | cpio -oc > /dev/rmt/n
and press Return. All of the files in the cwd directory are copied to
the tape in the drive you specify(n), overwriting any existing files on
the tape. The total number of blocks copied is displayed.
HOW TO LIST THE FILES ON A TAPE
Note -- Listing the table of contents takes as long as it does to read
the archive file because the cpio command must process the entire
archive.
Type:
cpio -civt < /dev/rmt/n
and press Return. The I option reads in the contents of the tape. The
v option displays the output in a format similar to the output from the
ls -l command. The t option lists the table of contents for the files
on the tape in the tape drive you specify.
HOW TO RETRIEVE ALL FILES FROM A TAPE
If the archive was created using relative path names, the input files
are built as a directory within the current directory. If, however, the
archive was created with absolute path names, the same absolute paths
are used to re-create the file (just as tar would do).
Caution -- Using absolute path names CAN BE dangerous because you will
overwrite the original files.
Type:
cpio -icv < /dev/rmt/n
and press Return. All of the files on the tape in the drive you specify
are copied to the current directory.
HOW TO RETRIEVE A SUBSET OF FILES FROM A TAPE
You can reload a subset of the files from the archive by specifying a
pattern to match using shell wild card characters enclosed in quotes
after the options.
Type:
cpio -icv "*file" < /dev/rmt/n
and press Return. All of the files that match the pattern are copied to
the current directory. You can specify multiple patterns, but each must
be enclosed in double quotation marks.

9. Can I dump my fs to a remote host?
Here's a command that can be used (note, be sure .rhosts on remote host
is set up)...
% ufsdump 0f - /other | ( rsh -l root "cd ;ufsrestore
xvf - " )
In this example, remove the with the actual name of the host
and the file system to be copied, just in case this was not obvious.

10. What is a stacker (autoloader) vs a jukebox?
An often confused matter is the differences between a stacker, also
known as an autoloader, and a jukebox.
There are 2 modes of operation for multi-tape loading devices:
sequential and random access.
Sequential mode does not ask for direction from the host system as to
what tape to deliver to the tape drive next. It simply sleeps until the
tape in the drive is ejected. At that point the, autoloader (or
stacker) will remove tape from the drive, place back in original slot in
tray and grab the next sequential tape in the tape tray, then sleep
again.
The mode described as jukebox, or random access, mode requires 3rd party
software (ie networker) to instruct the loading mechanism, which of the
tapes in the device to load into the tape drive. It does not do any
autoloading INDEPENDENT of the host machines software instruction.